J-PARC E19 experiment; Pentaquark search in hadronic reaction at J-PARC

J-PARC E19実験; ハドロン反応を用いたペンタクォーク探索

高橋 智則*; 江川 弘行; 早川 修平; 細見 健二  ; 市川 裕大   ; 今井 憲一; 佐甲 博之   ; 佐藤 進  ; 杉村 仁志; 谷田 聖   ; J-PARC E31 Collaboration*; 他64名*

Takahashi, Tomonori*; Ekawa, Hiroyuki; Hayakawa, Shuhei; Hosomi, Kenji; Ichikawa, Yudai; Imai, Kenichi; Sako, Hiroyuki; Sato, Susumu; Sugimura, Hitoshi; Tanida, Kiyoshi; J-PARC E31 Collaboration*; 64 of others*

A search for the pentaquark in the reaction was performed at the J-PARC Hadron Facility. Two data samples were collected in 2010 and 2012 at beam momenta of 1.92 and 2.0 GeV/, respectively. No peak structure was observed in the missing mass spectra obtained from either data set. The upper limit for the production cross section averaged over the scattering-angle range of to in the laboratory frame was found to be 0.28 b/sr. The decay width of the can be directly connected to the production cross section through a theoretical calculation using an effective Lagrangian. The estimated upper limits of the width were 0.41 and 2.8 MeV for the spin-parities of and , respectively.